1. Technical Field
The present specification relates to a power supply system for a vehicle, more particularly, to a power supply system for a vehicle that can be charged by use of an electric power from an external power supply provided outside the vehicle.
2. Description of Related Art
In recent years, as an environmentally friendly vehicle, a vehicle that is provided with a power storage device (e.g., a secondary battery, a capacitor, and the like) and runs by use of a driving force generated from an electric power stored in the power storage device has attracted attention. Such a vehicle includes an electric vehicle, a hybrid vehicle, a fuel-cell vehicle, and the like, for example. Further, there has been proposed a technique to charge a power storage device to be provided in these vehicles by a commercial power supply with high power generation efficiency.
Japanese Patent Application Publication No. 2011-160604 (JP 2011-160604 A) describes that, in such a vehicle, welding check is performed on a relay provided in a charge path from a vehicle external portion.
In JP 2011-160604 A, in order to perform the welding check on the relay, a voltage sensor is used. However, even in a case where an output value of the voltage sensor indicates an abnormal value, it is also conceivable that the voltage sensor itself is defective. Accordingly, depending on a situation, there is such a possibility that it is unclear whether the abnoiinal value is caused due to a welding defect of the relay or due to a defect of the voltage sensor. Accordingly, in order to determine an operation restriction range at the time of an occurrence of troubles or a replacement part at the time of repair, it is desirable that a defective range be specified in detail.